The present invention relates to an assembly conveyor including two conveyor bands displaceable in opposite directions and defining oppositely arranged assembly work stations, and a transverse conveyor which is provided at a discharge end of one of the conveyor bands for transferring assembly objects to another conveyor band.
The assembly conveyor generally includes continuously or cyclically operating transfer devices which transfer an assembly object from one work station to another. However, local conditions, such as space consideration, make it often impossible to arrange the work stations linearly, one after another. In this case, two rows or more of work stations, which extend parallel to each other, are provided.
Independently of whether each separate work station defines a manual assembly position or a fully automatic assembly position, the position of the handled object, the assembly element with respect to the assembly worker or an automatic assembly device should be constant, not changeable.
When the work stations are arranged opposite each other, i.e., arranged along two conveyor bands running in opposite directions, it is not sufficient to transfer the assembly object from one conveyor band to another without rotating it. This is because when transfer is effected without rotating the object, the object would face the worker or the automatic assembly device from a wrong side.
Numerous devices are used for rotating an object upon its transfer to the parallel conveyor band. These devices include lifting and rotating devices which cooperate with the transfer devices. However, to provide for proper cooperation of the transfer and rotating devices, rather expensive constructions have to be used because they require transverse displacement of linearly movable objects for effecting rotation.
German patent 2,259,273 discloses a device for the transfer of units from a roller conveyor. The device comprises at least one traction element, which is displaceable transverse to the roller conveyor and under the unit for sidewise displacement of the unit out of the region of the roller conveyor. The traction element has at least two spaced entrained members arranged one after another, with each being associated with a raised cam strip, which extends along the transfer path for lifting and lowering the transferred unit.
In the above-described case, the unit can be considered as an assembly object which is transferable from one conveyor band to another. However, the transfer device does not provide for rotation of the transferable unit or object.
Accordingly, an object of the present invention is to provide a device for transferring an object from one conveyor band to another conveyor band, which extends parallel to the one conveyor band and runs in an opposite direction, with the object being rotated as it moves along a transfer path, so that the same side of the object, which faces the work stations defined by the one conveyor band or a related side of the object, will face the work stations defined by another conveyor band.